make-or-break

(idiom) a thing that decides success or failure

Example Sentences:

The final exam in high-school is a make-or-break exam, because it determines if you will go to University or not.

This is a make-or-break situation. If the team loses, they are out of the finals!

From the Blogs:

Six flags prepares for Make or Break season

Media:

Similar idioms:

1. do or die
2. on a wing and a prayer
3. clean break
4. tip my hat to someone
5. hat off to someone
6. break a leg
7. in hot water
8. jump on the bandwagon